Byun S M, Jenness R
Biochemistry. 1981 Sep 1;20(18):5174-7. doi: 10.1021/bi00521a011.
Partially purified preparations of L-myo-inositol.-1-phosphate synthase (EC 5.5.1.4) from testis and mammary gland of laboratory rats (Rattus norvegicus) were used to show that this enzyme is specific for the pro-S hydrogen at C-4 of its cofactor, nicotinamide adenine dinucleotide (NAD). pro-S specificity of the first step (reversible oxidation of glucose 6-phosphate to 5-ketoglucose 6-phosphate) was proved by showing that tritium is transferred from [pro-S-4-3H]NADH but not from [pro-R-4-3H]NADH to glucose 6-phosphate when they are incubated with enzyme. That the stereospecificity in the second oxidation--reduction step (reduction of myo-inosose-2 1-phosphate to myo-inositol 1-phosphate) is the same as in the first step was shown by demonstrating that tritium from [5-3H]glucose 6-phosphate is incorporated into myo-inositol but not into NAD+ and that tritium from [4-3H]NAD+ is not incorporated into myo-inositol
使用从实验大鼠（褐家鼠）的睾丸和乳腺中部分纯化的L-肌醇-1-磷酸合酶（EC 5.5.1.4）制剂，来证明该酶对其辅因子烟酰胺腺嘌呤二核苷酸（NAD）的C-4位上的前-S氢具有特异性。第一步（将6-磷酸葡萄糖可逆氧化为5-酮基葡萄糖6-磷酸）的前-S特异性通过以下实验得以证明：当将[前-S-4-³H]NADH与[前-R-4-³H]NADH分别与酶一起孵育时，³H从[前-S-4-³H]NADH转移至6-磷酸葡萄糖，而不从[前-R-4-³H]NADH转移。通过证明³H从[5-³H]6-磷酸葡萄糖掺入肌醇而不掺入NAD⁺，以及³H从[4-³H]NAD⁺不掺入肌醇，表明第二步氧化还原步骤（将肌醇-2-磷酸还原为肌醇-1-磷酸）中的立体特异性与第一步相同。
